<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* .box
        {
           width: 300px;
           height: 300px;
           background-color: red;
           box-sizing: border-box;
           padding-left: 100px;
           padding-top: 100px;
        }
        .container
        {
           width: 100px;
           height: 100px;
           background-color: green;
        } */

        *
        {
            padding: 0px;
            margin: 0px;
        }

         .box
        {
           width: 300px;
           height: 300px;
           background-color: red;
           /* border: 1px,solid; */
           /* overflow: auto; */
           /* outline: 5px solid green;  */
           /* padding: 0px;
           margin: 0px; */
        }
        .container
        {
           width: 100px;
           height: 100px;
           background-color: green;
           /* margin-left: 100px;
           margin-top: 100px; */
           /* border: 1px ,solid; */
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="container">
        </div>
    </div>
</body>
</html>